Black Rats: (Rattus rattus)

• There are far fewer black rats in the UK than brown rats. They prefer to be around ports and this is why they are commonly referred to as ‘Ship Rats’.
• Black rats were the ones that carried the flea that was responsible for the bubonic plague.
• In the wild, they dwell in trees and are excellent climbers.
• They usually weigh approximately 225 grams but they have longer tails than brown rats.
• Although they eat different types of plant and animal matters, they prefer to eat grain.
• The female can produce up to 6 litters a year, each of around 8 young rats. Within a coupl of months the young are breeding for themselves. To put it another way, within a year it could be possible for one pair of black rats to produce a million descendants in just one year.
• The track mark of the black rat is similar to that of the brown rat but the tailmark is conspicuous.

Brown Rats: (Rattus norvegicus)

• Brown rats cat be found wherever there are humans. They are the type that is bred as pets and used in medical research.
• They are the most common animal in the UK.
• They are bigger than the black rat and an adult weighs roughly 400 grams. Average body length is 25cm although they can grow to be as long as 40cm (not including the tail, which on average is 19cm long)
• The brown rat is a nocturnal animal, although scarcity of food may lead it to come out during the day.
• They prefer to be outdoors and are more likely to infest around a building rather than inside it.
• Although they can create their own burrows they are just as happy to use man-made ones (eg: sewers) to get around.
• They are not fussy eaters and will eat whatever food they can find.
• They live in extended family groups that usually have only one dominant male.
• The track left behind by a brown rat is distinct. It is small, four-fingered front feet and long heel impressions. The tail mark is always visible.

Image via Wikipedia